I am also in the proccess of aquiring my wedding clothes and have dealt with sililar quandries, albeit absent of any stringent direction from my fiance.
Ultimately my choice was between a tux or a navy suit. I went with the latter as I feel it will be more useful in the future. In my opinion, if you wear a tux, then so should your groomsmen, the brides father, and frankely all of the other male guests as well. This modern American invention of the tuxedo wedding uniform...

That was my thought when I first put it on. I had the sleeves shortened a touch already, but I think I could have gone with a bit more. Not sure its worth paying for twice though. Maybe I'll get around to it one day.